Trammel.



PATBNTED MAY 23, 1905.

P. E. -BUXT0N- I ,TRAMMEL vAPPLICATION FILED 00T. 31,1903.

- 3 SHEETS-SHEET 1.

PATBNTED MAY 23, 1965.

P EQ BUXTON. TRAMMEL. APPLICATION FILED O0T.31,1903.

,PATENTBD MAY 23, 1905. Y P. E. lBUXTON.

TRAMMEL. APPLIGATION FILED 00T. 31,1903.

f 3 SHEETS-SHEET 3.

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drill/lll UNITED STATES Patented May 23, 1905.

PATENT OEEICE.

TRAIVIMEL.

A SPECIFICATION forming' part of Letters Patent N 0. 790,286, dated May 23, 1905.

Application filed October 3l, 1903. Serial No. 179,339.

To all whom t may concern:

Be it known that I, FRANCIS ELswoRTI-I BUXTON, a lcitizen of theUnited States, residing at St. Louis, in the State of Missouri, have invented a new and useful Trammel, of which the following is a specification.

My invention is an improved trammel, the improvements relating to the trammels, points, and the beam and the objects of my improvements are to provide a beam in sections which can conveniently be joined and the joints of which will present no obstacle to the movement of the trammels along the beam, to provide a beam of wedge-like crosssection and a trammel with a corresponding eye whereby the method of pivoting the points to the trammel which will be hereinafter set forth and described.

In the accompanying drawings, Figure l is a side elevation of my improved beam and trammels. Fig. 2 is an end view of same looking toward the describing-point. Fig. 3 is a similar view looking toward the centering-point, the caliper being removed. Fig. 4L is a detail of a detachable center-point rest. Fig. 5 is a perspective view showing two sections of the beam detached. Fig. 6 is a longitudinal section of the trammel, the beam being shown in elevation and illustrating one method of adjusting the describing-point. Fig. 7 is a sectional view about on the line '7 7 "of Fig. 6. Fig. 8 is a view somewhat similar to Fig. 6, illustrating a modification and showing a caliper attached to the describingpoint. Figs. 9 and 10 are detail views showing pen attachments. Fig. l1 is an outline view showing the manner of taking outside measurements. Fig. l2 is a similar view showing the manner of taking inside measurements. Fig. 13 is a longitudinal section j through the meeting ends ofthe beam. Fig.

14 is a section on the line x of Fig. 13. Fig. l5 is a section on the line y jz/ of Fig. 13.

In the construction of my improvement I use a hollow rectangular beam A in two or more sections, one section and apart of a second section being shown in the drawings. The beam A is wedge-shaped in cross-secthe beam and trammel Inay befirmly united, and contam improvements 1n tion, its side walls being downwardly convergent. In an end of one section is brazed or riveted a brass casting A', adapted to iit within the end of the other section, as is most clearly shown in-Figs. 5 and 13. This casting is centrally cut out to lighten it and carries longitudinally a rod A2, having a threaded projecting end.` At its rear inner end the rod has a milled head A3, rotating in an opening formed in the casting, which opening registers'with an opening A4, formed Vin the beam. In the opposite coacting section is arranged a casting A, having a threaded socket adapted to receive the threaded end of the rod A2.

The trammels B are composed of two vertical side members united at the top. In the lower portion of the trammel the side members are parallel. In the upper portion the members are downwardly convergent, the angle corresponding with the side walls of the beam. The length of this portion of the vtrammel exceeds the vertical depth of the beam and is adapted to slide on same. The inward and downward inclination of the walls of the upper portion of the trammel producesv a shoulder at the end of this portion, as shown at B, Fig. 7. At the sides and beneath the beam the trammel carrying the describingpoint is formed with downwardly-extending lugs 'B3 B4. Both lugs are formed with centrally-registering perforations, the one in the lug B3 being interiorly threaded and-larger than the perforation in the outer lug. In this larger perforation fits a threaded thumbnut C, also formed with a threaded perforation. A draw-screw C,having a smooth end slidingly iitting into the perforation in the lug B4, `has left-hand threads cut upon its opposite' end C2 and engages the threaded perforation of the nut, the exterior threads of which are right-handed. The function of this construction will be explained hereinafter.

The top-connecting member of the trammel has a threaded perforation in which works the thumb-screw D, the lower end of which is adapted to bear against the upper edge of the beam and to force same downwardly into binding engagement with the inner converging faces of the trammel.l

IOO

' tofore described that by turning the thumbnut so that it will move outwardly with reference to the lug of the trammel the drawscrew C will move inwardly and that the trunnions E3 will swing the head in the direction of movement of the draw-screw, the point of the describing member or point E moving in the same direction as the positive movement imparted to the thumb-nut.

In Fig. 4 I have shown an inverted cone F,

having a similar-shaped socket F produced in its base. This cone is adapted to fit in a hole drilled in a pattern, for example, and the socket will serve as a seat for the point of the centering-point G. The trammel carrying this point has a socket Gr transversely perforated through one wall, in which works the thumb-screw G2, which engages the upper end of the point and binds same securely in place.v By removing the point a pencil or draftsmans pen can be inserted and held in the socket, as shown in Fig. 10.

In Fig. 8 a modified form is shown, in which the upper part of the point E terminates in a segment H, which engages a wormgear H', formed on the draw-bar H2, which is rigidly secured to and turns with the thumb-screw H3, the other parts being similar to those shown in Fig. 6. In the lower part of Fig. 8 I have shown a method of securing a caliper to the point E. The caliper has upwardly-extending arms I2 and crossbands I3, the upper band being cut and the ends turned outward and perforated, forminglugs, and abinding-screw I4passes through them. The point E rests between the arms and bands, and the whole is bound together by the screw I4.

It will be observed that the trammels can slide along the beam from one section to another and that the side movement of the point E is in the same direction as that given. the thumb-screw which adjusts it. In Fig. l have shown the caliper placed on the rigid trammel-point,and in Fig. S I have shown it used on the pivoted point. It is obvious that it may be used on either point or omitted when not required. Its use on the rigid point is illustrated.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A device of the kind described comprising a hollow sectional beam, one of said sections being out out adjacent the end, a casting secured in the end of said section and adapted to fit in the other section, a threaded. rod having a milled head carried by the casting, a casting havinga threaded socket adapted to receive said rod arranged in the other section, trammels carrying points slidably mounted on the beam, and calipers adapted to be secured to said points.

2. In a device of the kind described, the combination with a sectional hollow, rectangular beam having inwardly and downwardly inclined sides, the end of one of the sections being reduced and adapted to [it into the end. of the adjoining section, of trammels, having side members inclined to correspond to the walls of the beams, points secured to the trammels, and a caliper adapted. to be secured to either of the points.

3. The combination with a suitable beam, of a trammel adapted to slide on said beam,

a describing-point pivotally secured to theI trammel, lugs formed on the trammel and having alining perforations one of which is threaded, a draw-screw threaded adjacent one end and adapted to workin the unthreaded perforation of the lug, a threaded thumbnut adapted to work on the draw-screw and in the threaded perforation, and means carried by the draw-screw adapted to swing the describing-point.

FRANCIS EhSWOll'lll BUX'ION.

Witnesses:

JAS. CUNNrNGI-misf, A. NTIssEN. 

